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Galaxias activas. Un flujo de salida rápido y de larga duración del agujero negro supermasivo en NGC 554848
J S Kaastra1, G A Kriss2, M Cappi3
1SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, Netherlands. Department of Physics and Astronomy, Universiteit Utrecht, Post Office Box 80000, 3508 TA Utrecht, Netherlands. Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands. j.kaastra@sron.nl.
Science (New York, N.Y.)
|July 5, 2014
Resumen
Una corriente de gas recién descubierta en la galaxia activa NGC 5548 oscurece significativamente su núcleo, bloqueando las emisiones de rayos X y causando la absorción de rayos UV. Esta salida rápida puede originarse en el disco de acreción que rodea al agujero negro supermasivo.
Área de la Ciencia:
- La astronomía y la astrofísica.
- La investigación de los núcleos galácticos activos (AGN, por sus siglas en inglés)
- Física de los agujeros negros.
Sus antecedentes:
- Los agujeros negros supermasivos (SBH) alimentan a las galaxias activas expulsando gas ionizado.
- NGC 5548, una galaxia activa arquetípica, exhibe un flujo de salida ionizado persistente conocido.
- Estudios anteriores utilizaron observaciones de rayos X y UV para caracterizar las salidas de AGN.
Objetivo del estudio:
- Para investigar el fenómeno de oscurecimiento observado en NGC 5548 durante una campaña de observación de 2013.
- Para caracterizar las propiedades y el origen de un flujo de gas recién identificado.
- Para entender el impacto de este gas oscurecedor en el núcleo galáctico activo.
Principales métodos:
- Observaciones coordinadas utilizando seis observatorios espaciales.
- Espectroscopia de rayos X y ultravioleta (UV) de alta resolución.
- Análisis de los efectos de oscurecimiento en la radiación emitida.
Principales resultados:
- Se detectó una corriente gruesa de gas ionizado de larga duración que oscurecía el núcleo de NGC 5548.
- Este gas bloqueó aproximadamente el 90% de las emisiones suaves de rayos X.
- Simultáneamente se observaron profundas y amplias depresiones de absorción UV, lo que indica altas velocidades (hasta cinco veces más rápidas que el flujo de salida persistente).
Conclusiones:
- La corriente de gas recién descubierta representa una característica significativa y no observada previamente en NGC 5548.8.
- Las altas velocidades de salida y la proximidad (unos pocos días luz) sugieren un origen en el disco de acreción.
- Este hallazgo proporciona nuevos conocimientos sobre la compleja dinámica y los mecanismos de oscurecimiento en los núcleos galácticos activos.
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